On December 21, 2009, the U.S. Air Force Weather Agency reported that Soufriere Hills Volcano on the Caribbean island of Montserrat released continuous plumes of ash and steam, some of them extending 35 nautical miles (65 kilometers) southeast of the summit. The same day, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this true-color image.

The plume from Soufriere Hills is thick enough to completely hide parts of Montserrat from the satellite’s view. Although plumes from Soufriere Hills frequently blow toward the west or northwest, this plume blows toward the southeast. The plume’s beige color suggests that plenty of volcanic ash is mixed with water vapor.

Soufriere Hills is a stratovolcano composed of alternating layers of volcanic ash, lava, and rocks released by earlier eruptions. Rising to a height of 3,002 feet (915 meters), the volcano fills the southern half of Montserrat. Observers noted a seventeenth-century eruption at Soufriere Hills, after which the volcano remained quiet until 1995.